Production of granular mixtures

ABSTRACT

Process for producing granular enzyme product which comprise mixing an aqueous slurry of powdered enzyme preparation with hydrated pentasodium tripolyphosphate while agitating.

United States Patent [1 1 Hussain Nov. 20, 1973 [54] PRODUCTION OFGRANULAR MIXTURES [7 5] Inventor: Ali Ghalib Mohammed Hussain,

, Elizabeth, NJ. i

[73] Assignee: Colgate-Palmolive Company, New

York, NY.

22 Filed: Sept. 8, 1971 21 Appl.No.: 178,800

Related U.S. Application Data [63] Continuation of Ser. No. 828,938, May29, 1969,-

abandoned.

[52] U.S. Cl. 252/89, 195/63, 252/135, 252/DIG. 12 [51] Int. Cl Clld7/42 [58] Field of Search 252/89, 135, 137;

[56] References Cited UNITED STATES PATENTS 3,451,935 6/1969 Roald3,519,570 7/1970 McCarty 252/89 FOREIGN PATENTS OR APPLICATIONS 16,5013/l959 Germany 252/89 Primary ExaminerWilliam E. Schulz Attorneyl-lerbert S. Sylvester et al.

[57] ABSTRACT Process for producing granular enzyme product whichcomprise mixing an aqueous slurry of powdered enzyme preparation withhydrated pentasodium tripolyphosphate while agitating.

3 Claims, 4 Drawing Figures Imm L PRODUCTION OF GRANULAR MIXTURES Thisis a continuation of application Ser. No. 828,938 filed May 29, 1969now. abandoned.

This invention relates to a method of making a granular non dustingdetergent composition for use in laundry products.

Powdered enzymes have been employed in presoak and washing detergentcompositions since they are particularly effective against variouscommon stains which are fixed to textiles and laundry. In particular;proteolytic enzymes, which possess the ability to digest and degradeprotein matter, are effective in removing from textiles and laundryproteinic stains such as blood, sweat, milk, cocoa, gravy and othersauces and the like. The digestion or degradation of proteinmatterfacilitates removal of dirt by the detergent. Amylases and lipasos arealso useful in detergent cleaning.

However, the use of powdered enzymes in such compositions has resultedin certain problems including the presence of an excessive amount ofdust. Some individuals experience allergic reactions to the enzyme dust.Furthermore, detergent compositions containing enzymes have been subjectto discoloration, formation of undesirable odor and caking.

It has been suggested to bind variouscompounds which are common buildersalts in their hydratable form with enzymes. This may be done bycontacting enzyme with an anhydrous or partially hydrated salt andadding water in insufficient amount to fully hydrate the salt. Aconsiderable amount of enzyme dust is still present when theenzyme-hydratable salt composition is used. Discoloration and odorformation may also occur.

One aspect of this invention relates to the production of granules orbeads containing the enzyme preparation and pentasodium tripolyphosphate(hereafter termed TPP) by mixing an aqueous slurry of the enzymepreparation with finely divided hydrated TPP. The invention provides arapid convenient and economical method for producing a granular enzymeproduct which has good stability. It makes it possible to produce aproduct in which any dust is much lower in enzyme content than theproduct itself.

In one embodiment of the process the finely divided TPP is added to theaqueous slurry of powdered enzyme preparation while agitating, so thatthe slurry coats the surfaces of the hydrated TPP, the amount of waterpresent being such as to provide a total water content (including waterof hydration introduced with the TPP) of about 35 to 55 parts of waterper 100 parts of TPP, calculated as anhydrous TPP. This proporation ofwater is in excess of the amount present in TPP hexahydrate, whose watercontent is'29.4 parts of water per 100 parts of TPP, calculated asanhydrous TPP. During mixing it is found that the mixture formsgranules. This may be caused, I believe, by the acceleration of fineparticles of the hydrated TPP to larger particles thereof or toagglomerates (of fine particles) produced in earlier stages of mixing.These granules, while more orless dry to the touch, are caky"; that is,the granules can be squeezed together in the hand to form a coherentmass or cake. in contrast, when hydrated sodium sulfate is substitutedfor the hydrated TPP a mushy mudlike mixture is obtained.

The formation of a slurry and the addition of the'TPP thereto, insteadof spraying the slurry onto the granular TPP has many advantages. ltmakes it possible to use smallerequipment, less expensive equipment,less manpower and less mechanical power.

The caky granules are then dried,- preferably in a fluidized bed in astream of heated. air, at a relatively low temperature. Thus, thetemperature reached in the bed may be in the range of about 40-60C-preferably about 4555C (e.g. about 50C); the temperature may be measuredby simply inserting a thermometer into. the fluidized bed during drying.During drying the total water content is reduced to a level of about 20to 30- parts of water per 100 parts of TPP (calculated as anhydrousTPP). The particle size distribution is substantially the same beforeand after the drying in the fluidized bed.

The resulting granular product is free-floating, has a low finescontent, and shows good enzyme stability; even to.aging at 100 percentrelative humidity at 49C. for one week the loss of enzyme activity is,say, about 25 percent.

In a preferred embodiment of the invention the hydrated TPP used as astarting material is itself a granular product of which over 40 percent(by weight), e.g. 50-70 percent, will be retained on 40 mesh sieve,having 0.42 mm openings; all sieve sizes given herein are U.S.Standard.Preferably substantially none of the material is retained on a 10 meshsieve (whose openings are 2 mm in diameter). Very good results have beenattained using a commercial grade of TPP hexahydrate which has a water.content of about -85 percent of that theoretically present in thehexahydrate; thus one commercial TPP hexahydrate has a water content of18.3 percent based on the total weight (while pure TPP hexahydrate has awater content of 22.7 percent, based on total weight); a TPP content(calculated as anhydrous TTP) of 76 percent; a pryophosphate content, asNa P O- of 3.5 percent; an orthophosphate content, as Nag-IP0 of 0.3percent; and a sodium thrimetaphosphate content, as NaPO of 1.9 percent.

The whole process can be effected very rapidly, using relativelyinexpensive equipment. Thus the whole step of mixing the enzyme slurryand the hydrated TPP and forming caky granules therefrom can be effectedin less than 5 minutes in a simpleRoss mixer and the material can thenbe delivered directly to the fluidized bed drier in which the drying canbe effected in, say 5-l5 minutes, preferably about 10 minutes. I havefound that the presence of the enzyme preparation appears to inhibit therate of hydration of TPP; thus when partly hydrated TPP is used. as thestarting material little, if any, hydration thereof occurs during mixingor drying.

The slurry of powdered enzyme preparation can be relativelyconcentrated, e.g. it may contain 100, 200,

300 or 400 parts of powdered enzyme preparation per parts of water.Especially good results have been obtained with slurries containingabout 200 to 300 parts of powdered enzyme preparation per 100 parts ofwater. Typically the slurry is a mud-like mixture. When the hydrated TPPis added gradually the mixture thickens, then forms relatively large(about 2-5 cm in diameter). but very fragile aggregates which becomesmaller and smaller as the addition of'hydrated TPP with agitationcontinues. it is preferred to add the hydrated TPP at such a rate thatsubstantially all the TPP becomes mixed in with the slurry (e.g. thehydrated TPP is added gradually, with. agitation, over a period of atleast /2 minute, but less than about 5 minutes, preferably about 1 to 2minutes).

Particularly good results are obtained using a well known Ross mixerwhich is of the double planetary type having a pair of mixing bladeswhich rotate in overlapping circular paths about their parallel verticalaxes while the axes themselves move in a circular path about thevertical axis of the mixing vessel and close to its cylindrical wall.Also useful are the well known Hobart mixer (which is of a singleplanetary type) or a ribbon mixer (e.g. a conventional Day mixer).

Preferably the process is carried out in such fashion as to producegranules which pass through a 10 mesh sieve (sieve opening 2 mm), morepreferably pass through a 20 mesh sieve (sieve opening 0.84 mm) and areretained on an 80 mesh sieve (sieve opening 0.177 mm); the granuleswithin that size range more preferably constitute a major portion (mostpreferably being at least about 60 percent, e.g. about 60 to 80 percent)of the total weight of the product.

In the preferred form of the invention the enzyme comprises aproteolytic enzYme which is active upon protein matter and catalyzesdigestion or degradation of such matter when present as in linen orfabric stain in a hydrolysis reaction. The enzymes may be effective at apH range of say about 4-12, and may be effective even at moderately hightemperatures so long as the temperature does not degrade them. Someproteolytic enzymes are effective at up to about 80C. and higher. Theyare also effective at ambient temperature and lower to about 10C.Particular examples of proteolytic enzymes which may be used in theinstant invention include pepsin, trypsin, chymotrypsin, papain,bromelin, colleginase, keratinase, carboxylase, amino peptidase,elastase, subtilisia and aspergillopepidase A and B. Preferred enzymesare substilisin enzymes manufactured and cultivated from special strainsof spore forming bacteria, particularly bacillus subtilis.

Proteolytic enzymes such as Alcalase, Maxatase, Protease AP, ProteaseATP 40, Protease ATP 120, Protease L-252 and Protease L-423 are amongthose enzymes derived from strains and spore foaming bacillus, such asbacillus subtillis.

Different proteolytic enzymes have different degrees of effectiveness inaiding in the removal of stains from textiles and linen. Particularlypreferred as stain removing enzymes are subtilisin enzymes.

Metalloproteases which contain divalent ions such as calcium, magnesiumor zine bound to their protein chains are of interest.

The enzyme preparations are generally extremely fine, oftensubstantially impalable, powders. In a typical powdered enzymepreparation the particle diameter is mainly below 0.15 mm, generallyabove 0.01 mm,

I e.g. about 0.1 mm; for example, as much as 75 percent of the materialmay pass through a 100 mesh (U.S. Standard) sieve. In contrast,conventional spray dried granules of detergent compositionsare usuallyof very much larger particle size, with the major portion of thegranules being at least about 0.2 mm in diameter, e.g.

about 0.3 or 0.4, or even 05, 1 or 2 mm.

The enzyme preparations are generally extremely diluted with salts suchas calcium sulfate and inert materials. Chemically .they are typicallystable in the pH range of 5 to and at an alkaline pH of 8.5 to 9. Theycan withstand temperatures of 49.C. to 77C. with relatively littledecomposition for time periods varying from 2 hours at the highertemperatures to more than 1 day at the lower temperatures. Differentproteolytic enzymes have different degrees of effectiveness in aiding inthe removal of stains from textiles and linen.

Instead of, or in additionto, the proteolytic enzyme, an amylase may bepresent such as a bacterial amylase of the alpha type (e.g. obtained byfermentation of B. subtilis). One very suitable enzyme mixture containsboth a bacterial amylase of the alpha type and an alkaline protease,preferably in proportions to supply about 100,000 to 400,000 Novoalpha-amylase units per Anson unit of said alkaline protease.

The enzyme content of the granules or beads can be varied widely, e.g.in the range of 2 50 percent of powdered enzyme preparation. When thepowdered enzyme preparation has an alkaline protease content of 1.5Anson units per gram, this range of course represents some 3 to Ansonunits per 100 grams of granules or beads. The invention finds itsgreatest utility, however, for the manufacture of granules or beadswhich are relatively rich in enzyme content, containing at least 10percent of the enzyme preparation (corresponding to say at least 15Anson units per 100 grams of the granules) and preferably at least 15percent. In the final washing product, made for example by blending theenzyme containing granules or beads with other granular material (suchas spray-dried hollow beads or spongeous low density granules), thecontent of powdered enzyme preparation is much lower, e.g. in the rangeof about 0.10 to 4.0 percent, preferably about 0.3 to 2.0 percent.

The amount of the enzyme mixture present in the detergent compositionwill, of course, depend to some extent on the amount of the detergentcomposition which is to be added to the wash water. For detergentcompositions which are intended for use at concentrations of, say, about0.15 percent in the wash water of an automatic home laundry machine, onesuitable amount of enzyme mixture is such as to provide 1 Anson unit ofthe alkaline protease for each 100 to 500 (e.g. 200 to 400) grams of thedetergent composition.

The enzyme-containing granules or beads produced in accordance with thisinvention may be added to a wide variety of washing products. Thus, theymay be incorporated in a laundry presoak product or in a laundrydetergent or in a dishwashing product. A typical presoak productcontains a relatively high concentration of builder salt such as about30 to percent penta-sodium tripolyphosphate (calculated as anhydrouspentasodium tripolyphosphate), about 2 to 10 percent of organic surfaceactive detergent, plus other ingredients such as sodium silicate (whichacts as a builder salt and also acts to inhibit corrosion of aluminumsurfaces), brightening agents and sodium sulfate. A laundry detergentgenerally has a lower ratio of builder salt to organic surface activeagent (e.g. a ratio in the range of about 5:1 to 15:1). Dishwashingproducts, designed for use in automatic dishwashers, are on the otherhand usually more alkaline, containing a very high proportion ofalkaline builder salt, such as a mixture of the pentasodiumtripolyphosphate and sodium silicate; they contain little, if any,organic surface active detergent, e.g. about 0.2 to 3 percent andusually also contains a minor proportion (e.g. 0.5 to 5 percent) of anagent to prevent water-spotting such as a dry watersoluble compoundwhich on contact with water, liberates hypochlorite chlorine (e.g. aheterocyclic dichloroisocyanurate); alternatively, a chlorinatedphosphate (such as the well known chlorinated trisodium phosphate) maybe used to supply both hypochlorite chlorine and some phosphate.

ln formulating the washing products, the watersoluble builder salts maybe phosphates and particularly condensed phosphates (e.g. pyrophosphatesor tripolyphosphates), silicates, borates and carbonates (includingbicarbonates), as well as organic builders such as salts ofnitrilotriacetic acid or ethylene diamine tetracetic acid. Sodium andpotassium salts are preferred. Specific examples are sodiumtripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate,sodium carbonate, sodium bicarbonate, sodium sesquicarbonate, sodiumtetraborate, sodium silicate, salts (e.g. Na salt) of methylenediphosphonic acid, disodium diglycollate, trisodium nitrilotriacetate,or mixtures of such builders, including mixtures of pentasodiumtripolyphosphate and trisodium nitrilotriacetate in a ratio, of thesetwo builders, of 1:10 to :1, e.g. 1:1.

The organic surface active agent may be an anionic, nonionic oramphoteric surface active agent; mixtures of two or more such agents maybe used.

The anionic surface active agents include these surface active ordetergent compounds which contain an organic hydrophobic group and ananionic solubilizing group. Typical examples of anionic solubilizinggroups are sulfonate, sulfate, carboxylate, phosphonate and phosphate.Examples of suitable anionic detergents which fall within the scope ofthe invention include the soaps, such as the water-soluble salts ofhigher fatty acids or resin acids, such as may be derived from fats,oils and waxes of animal, vegetable origin, e.g. the sodium soaps oftallow, grease, coconut oil, tall oil and mixtures thereof; and thesulfated and sulfonated synthetic detergents, particularly those havingabout 8 to 26, and preferably about 12 to 22, carbon atoms to themolecule.

As examples of suitable synthetic anionic detergents there may be citedthe higher alkyl mononuclear aromatic sulfonates such as the higheralkyl benzene sulfonates containing from 10 to 16 carbon atoms in thealkyl group in a straight or branched chain, e.g.', the sodium salts ofhigher alkyl benzene sulfonates or of the higher alkyl toluene, xyleneand phenol sulfonates; alkyl naphthalene sulfonate, ammonium diamylnaphthalene sulfonate, and sodium dinonyl naphthalene sulfonate. In onepreferred type of composition there is used a linear alkyl benzenesulfonate having a high content of 3- (or higher) phenyl isomers and acorrespondingly low content (well below 50 percent) of 2- (or lower)phenyl isomers; in other terminology, the benzene ring is preferablyattached in large part at the 3 or higher (e.g. 4, 5, 6 or 7) positionof the alkyl group and the content of isomers in which the benzene ringis attached at the 2 or 1 position is correspondingly low. Particularlypreferred materials are set forth in U.S. Pat. No. 3,320,174, May 16,1967, of J. Rubinfeld.

Other anionic detergents are the olefin sulfonates, including long chainalkene sulfonates, long chain hydroxyalkane sulfonates or mixtures ofalkenesulfonates and hydroxylalkane-sulfonates. These olefin sulfonatedetergents may be prepared, in known manner, by the reaction of S0 withlong chain olefins (of 8-25, preferably 12-21 carbon atoms) of theformula RCH=CHR,, where R is alkyl and R, is alkyl or hydrogen, toproduce a mixture of sultones and alkenesulfonic acids, which mixture isthen treated to convert the sultones to sulfonates. Examples of othersulfate or sulfonate detergents are paraffin sulfonates having, forexample, about 10-20, preferably about 15-20, carbon atoms such as theprimary paraffin sulfonates made by reacting long chain alpha olefinsand bisulfites (e.g. sodium bisulfite) or paraffin sulfonates having twosulfonate groups distributed along the paraffin chain such as theproducts made by reacting a long chain paraffin with sulfur dioxide andoxygen under ultraviolet light followed by neutralization with NaOH orother suitable base (as in U.S. Pat. Nos. 2,503,280; 2,507,088;3,260,741; 3,372,188 and German patent 735,096); sulfates of higheralcohols; salts of a-sulfofatty esters (e.g. of about 10 to 20 carbonatoms, such as methyl a-sulfomyristate or a-sulfotallowate).

Examples of sulfates of higher alcohols are sodium lauryl sulfate,sodium tallow alcohol sulfate, Turkey Red Oil or other sulfated oils, orsulfates of monoor di-glycerides of fatty acids (e.g. stearicmonoglyceride monosulfate), alkyl poly (ethenoxy) other sulfates such asthe sulfates of the condensation products of ethylene oxide and laurylalcohol (usually having 1 to 5 ethenoxy groups per molecule); lauryl orother higher alkyl glyceryl ether sulfonates; aromatic poly (ethenoxy)other sulfates such as the sulfates of the condensation products ofethylene oxide and nonyl phenol (usually having 1 to 6 oxethylene groupsper molecule).

The suitable anionic detergents include also the acyl sarcosinates (e.g.sodium lauroylsarcosinate) the acyl esters (e.g. oleic acid ester) ofisothionates, and the acyl N-methyl taurides (e.g. potassium N-methyllauroylor oleyl tauridge).

The most highly preferred water soluble anionic detergent compounds arethe ammonium and substituted ammonium (such as mono-, diandtriethanolamine), alkali metal (such as sodium and potassium) andalkaline earth metal (such as calcium and magnesium) salts of the higheralkyl benzene sulfonates, olefin sufonates, the higher alkyl sulfates,and the higher fatty acid monoglyceride sulfates. The particulsr saltwill be suitably selected depending upon the particular formulation andthe proportions therein.

Nonionic surface active agents include those surfaces active ordetergent compounds which contain an organic hydrophobic group and ahydrophilic group which is a reaction product of a solubilizing groupsuch as carboxylate, hydroxyl, amido or amino with ethylene oxide orwith the polyhydration product thereof, polyethylene glycol.

As examples of nonionic surface active agents which may be used theremay be noted the condensation products of alkyl phenols with ethyleneoxide, e.g., the reaction product of isooctyl phenol with about 6 to 30ethylene oxide units; condensation products of alkyl thiophenols with 10to 15 ethylene oxide units; condensation products of higher fattyalcohols such as tridecyl alcohol with ethylene oxide; ethylene oxideaddends of monoesters of hexahydric alcohols and inner ethers thereofsuch as sorbitan monolaurate, sorbitol monooleate and manitanmonopalmitate, and the condensation products mannitan polypropyleneglycol with ethylene oxide.

A particularly suitable composition, for use as a granular detergentmaterial contains a mixture of a linear alkylbenzenesulfonate, aspreviously described, soap and a non-ionic detergent, with the soap andnonionic detergent being present in minor portions. The ratios of theamounts of (A) soap, and (B) nonionic detergent, to (C) the total amountof the synthetic anionic sulfate and sulfonate detergent, in thismixture, are preferably as follows: AzC, about 1:10 to 1:2, preferablyabout 1:4 to 1:6, on an anhydrous basis; B:C about 1:10 to 1:3, e.g.about 1:4 to 1:6, on an anhydrous basis. The component (C) may comprisea blend of the linear alkylbenzenesulfonate detergent with other anionicsynthetic sulfate or sulfonate detergents (e.g. olefin sulfonates,paraffin sulfonates having the sulfonate groups distributed along theparaffin chain, or alkyl sulfonates) with the alkylbenzenesulfonateconsisting, say, '75, k or 36 of this blend.

Examples of suitable amphoteric detergents are those containing both ananionic and a cationic group and a hydrophobic organic group, which isadvantageously a higher aliphatic radical, e.g. of -20 carbon atoms.Among these are the N-long chain alkyl aminocarboxylic acids (e.g. ofthe formula the N-long chain alkyl iminodicarboxylic acids (e.g. of theformula RN(RCOOM) and the N-long chain alkyl betains (e.g. of theformula where R is a long chain alkyl group, e.g. of about 10-20carbons, R is a divalent radical joining the amino and carboxyl portionsof an amino acid (e.g. an alkylene radical of 1-4 carbon atoms), N ishydrogen or a salt-forming metal, R is a hydrogen or another monovalentsubstituent (e.g. methyl or other lower alkyl), and R and R aremonovalent substituents joined to the nitrogen by carbon-to-nitrogenbonds (e.g. methyl or other lower alkyl substituents). Examples ofspecific amphoteric detergents are N-alkyl-betaaminopropionic acid,N-a1ky1-beta-iminodipropionic acid, and N-alkyl, N,N-dimethyl glycine;the alkyl group may be, for example, that derived from coco fattyalcohol, lauryl alcohol, myristyl alcohol (or a lauryl-myristylmixture), hydrogenated tallow alcohol, cetyl, stearyl, or blends of suchalcohols. The substituted aminopropionic and iminodipropionic acids areoften supplied in the sodium or other salt forms, which may likewise beused in the practice of this invention. Examples of other amphotericdetergents are the fatty imidazolines such as those made by reacting along chain fatty acid (e.g. of 10 to carbon atoms) with diethyl enetriamine and monohalocarboxylic acids having 2 to 6 carbon atoms, e.g.l-coco-5-hydroxethyl-5-carboxymethylimidazoline; betaines containing asulfonic group instead of the carboxylic groups; betaines in which thelong chain substituent is joined to the carboxylic group without anintervening nitrogen atom, e.g. inner salts of 2-trimethylamino fattyacids such as 2-trimethylaminolauric acid, and compounds of any of thepreviously mentioned types but in which the nitrogen atoms is replacedby phosphorous.

Various other materials may be present in the granular products. Thus,materials such as the higher fatty acid amides maybe added to improvedetergency and modify the foaming properties in a desirable manner.Examples thereof are the higher fatty acid alkanolamides, preferablyhaving 2-3 carbons in each alkanol group and a fatty acyl radical withinthe range of 10-18 carbons, preferably 10-14 carbons, such as lauric ormyristic monothanolamides, diethanolamides and isopropanol-amides.Tertiary higher alkyl amino oxides such as having about l0-18 carbons inone alkyl group, e.g. lauryl of myristyl dimethylamine oxide, may beadded also. Fatty alcohols of 10-18 carbons such as lauryl or coconutfatty alcohols, or cetyl alcohol are suitable additives also. Ahydrotropic material such as the lower alkyl aryl sulfonates, e.g.sodium toluene or xylene sulfonates, can assist processing also. Ingeneral, these materials are added in minor amounts, usually from aboutk to 10 percent, preferably 1 to 6 percent, based on the total solids.

The mixtures may also contain optical brightening agents or fluorescentdyes (e.g. in amounts in the range of about 1/20 to k percent);germicidal ingredients such as halogenated carbanilides, e.g.trichlorocarbanide, halogenated salicylanilide, e.g.tribromosalicylanilide, halogenated bisphenols, e.g. hexachlorophene,halogenated trifluoromethyldiphenyl urea, zinc salt of1-hydroxy-2-pyridinethione and the like (e.g. in amounts in the range ofabout 1/50 to 2 percent); soil-suspending suspending agents such assodium carboxymethyl cellulose or polyvinyl alcohol, preferably both, orother soluble polymeric materials, such as methyl cellulose (the amountof suspending agent being, for example, in the range of about 1/20 to 2percent); antioxidants such as 2,6-di-tertbutylphenol, or other phenolicantioxidant materials (e.g. in amounts in the range of about 0.001 to0.1 percent), coloring agents, bleaching agents and other additives.

The following Examples are given to illustrate this invention further.In these Examples, as in the rest of the application, all proportionsare by weight unless otherwise specified. Also, in these Examples, thepressure is atmospheric unless otherwise specified.

EXAMPLE 1 A thin mud-like slurry is prepared in Standard Ross Mixer (ofthe double planetary type) by mixing at room temperature 24.0 parts ofpowdered proteolytic subtilisin enzyme preparation (Alcalase, 1.5 AnsonUnits/g) and 10.8 parts water. Then 65.2 parts of a commercial granularpentasodium tripolyphosphate hexahydrate are added granually, at therate of about 45 parts per minute; the mixing is continued for about 3minutes after addition of the pentasodium tripolyphosphate hexahydratehas concluded. in this example, the total weight of the batch is about90.9 Kg (200 lbs.), the volume of the mixing vessel is about 40 gallons,and the speed of rotation of the double blade about the axis of thevessel is about 26 RPM.

The pentasodium tripolyphosphate hexahydrate used in this Example hasthe following screen analyses:

Screen Mesh Opening (mm) Remaining on Mesh Fan Total 100.0

The results of another analysis of another portion of the same materialare: +10 mesh, 0 percent; +20, 1.5 percent; +30, 26 percent; +60, 83.9percent, -100 mesh, 2.4 percent. This TPP hexahydrate has a total watercontent of 18.3 percent, a free water content of 0.55 percent, of pH of9.87, a bulky density of 0.705 g/cc and a P content averaging 47.16percent.

The caky granules resulting from the mixing process are fed to afluidized bed drier where they are fluidized by a stream of heated airand subjected to the drying action of the air for a period of minutes ata bed temperature rising to 50C.

The product is a granular material containing the enzyme distributedthoroughly therein, showing very little if any tendency to dust andshowing very good resistance to loss of enzyme activity on aging. Itsscreen analysis (after removal of a very small portion of materialretained on a 10 mesh sieve) is as follows:

Screen Mesh Remaining on Mesh 20 l 1.7 40 47.0 60 26.8 80 8.4 100 2.5Pan 3.5

Total 99.9

The proteolytic subtilisin enzyme preparation used in the foregoingExample has its minimum proteolytic activity at a pH of 8 9. Thisactivity as measured at pH 7.5 on the commercial enzyme preparationavailable from Novo Industri A/S, Copenhagen, Denmark is about 1.5 AnsonUnits per gram of the enzyme. The commercial enzyme preparation is a rawextract of bacillus subtillis culture and contains about 6 percent ofpure crystallized proteolytic material. The preparation is an extremelyfine powder; typically the particle diameter is mainly below 0.15 mm,generally above 0.01

mm, e.g. about 0.1 mm, and as much as 50 percent or even 75 percent ofmaterial may pass through a 100 mesh sieve. The preparation containsabout 70 percent NaCl and about -18 percent Na SO Its organic content isin the neighborhood of 11 percent.

EXAMPLE 2 Example 1 is repeated except that one starts with an enzymepreparation which is richer in the enzyme. Here there are used 9.0 partsof enzyme preparation having an enzyme content of 4.0 Anson units pergram, 14.0 parts of water and 77 parts of the TPP hexahydrate.

EXAMPLE 3 The products of each of the foregoing Examples are dry blendedwith spray dried hollow beads ofa mixture of pentasodiumtirpolyphosphate, an organic detergent (sodium lineartridecylbenzenesulfonate), sodium silicate (Na- O:SiO ratio 1.012.35),optical brighteners, and sodium sulfate to give, in each case, acomposition having the following approximate analysis: total anhydrousphosphate solids 70 percent, organic detergent 6.75 percent, sodiumsilicate 5.1 percent, brighteners 018 Percent, 1 Qrwr (P or minu 12mm).the enzyme preparation 0.76 percent, and the balance being sodiumsulfate.

The resulting granular solid mixture is a highly effective presoakproduct, which is mixed with water (e.g. to form a 0.19 percent solutionof the whole solid mixture) and used for soaking soiled and stainedcotton garments or other fabric material (e.g. for l to 24 hours) priorto washing said fabric materials.

The accompanying drawings.are photomicrographs,

with the scale indicated for each picture for the material in theforeground. FIGS. 1, 2 and 3 are made with a conventional scanningelectron microscope (in which the specimen is scanned with an electronbeam, the electrons reflected from the surface of the specimen arecollected and used, through intermediate light signals, to modulate thescanning beam of a cathode ray tube to give a picture like that seen ona television screen); the specimens are pre-coated with a very thinlayer of conductive material (e.g. a 50A. thick layer of gold, appliedin a vacuum) as is conventional in the use of the instrument, to give aclearer picture. The scanning electron microscope has a much greaterdepth of field than an ordinary light microscope.

FIG. 1 shows two granules of the hydrated TPP (commercial porous TPPhexahydrate as used in the foregoing Examples). The wormy elements nearthe bottom of each granule are merely the adhesive used to attach thegranules to the base on which they rest in the instrument.

FIG. 2 shows a granule of the product of Example I. It can be seen thatthe granule includes attached smaller particles agglomerated therewith.

FIG. 3 is a view showing several granules of the product of Example 1.

FIG. 4 is a view of the granules of the product of Example l, taken witha light microscope using transmitted light, with the specimen immersedin oil (a conventional microscope technique). The transparent crystalsare believed to be sodium chloride crystals from the enzyme preparation;some of these have apparently been formed by solution in the aqueousmedium of the slurry followed by recrystallization.

It will be apparent that variations of the invention may be made andequivalents substituted therefor.

I claim:

1. Process for producing a granular enzymecontaining product whichcomprises adding porous granules of hydrated pentasodiumtripolyphosphate, whose water content is at least about percent of thatof pure pentasodium tripolyphosphate hexahydrate and whose particle sizedistribution is such that over 40 percent is retained on a 40 mesh sieveand substantially none is retained on a 10 mesh sieve, gradually to anaqueous slurry of protease enzyme fine powder while agitating,substantially all said tripolyphosphate being added to said slurry overa period of at least one half minute but less than five minutes, saidslurry containing about 200 to 400 parts of the enzyme powder per partsof water, the amount of water in the slurry being such as to provide insaid mixture a total water content (including water of hydration presentin said tripolyphosphate) of about 35 to 55 parts of water per 100 partsof pentasodium tripolyphosphate, calculated as anhydrous pentasodiumtripolyphosphate, whereby the resulting mixture thickens, then formsfragile aggregates which become smaller as the addition of said by:drated tripolyphosphate with agitation continues, forming caky granules,which if squeezed together in the hand will form a coherent mass, anddrying said caky granules to form free-flowing granules by subjectingsaid caky granules to air having a temperature of up to about 60C. untilthe total water content is reduced to about 20 to 30 parts of water per100 parts of pentasodium tripolyphosphate, calculated as anhydrouspentasodium tripolyphosphate.

2. Process as in claim 1 in which said caky granules content about 75-85percent of that of pure pentasoare dried in a fluidized bed at atemperature in the dium tripolyphosphate hexahydrate and said slurry isa range of about 40-60C.

3. Process as in claim 2 in which the granules of hydratedtripolyphosphate feed material have a water 5 mud-like mixture.

Dedication 3,773,671.-Ali Ghalz'b M ohammwd Husswin, Elizabeth, NJ.PRODUCTION OF GRANULAR MIXTURES. Patent dated Nov. 20, 1973. Dedicationfiled Mar. 20, 1980, by the assignee, Uolgate-Palmohve Oompwny.

Hereby dedicates to the Public the entire remaining term of said patent.

[Oyficz'al Gazette, M ay 20, 1980.]

2. Process as in claim 1 in which said caky granules are dried in afluidized bed at a temperature in the range of about 40*-60*C. 3.Process as in claim 2 in which the granules of hydrated tripolyphosphatefeed material have a water content about 75-85 percent of that of purepentasodium tripolyphosphate hexahydrate and said slurry is a mud-likemixture.